Three-dimensional effects in vortex-gust wing interaction

Unmanned aerial vehicles (UAVs) - including micro air vehicles, delivery drones, and urban air taxis - are becoming increasingly widespread. Unlike traditional aircraft, UAVs operate at lower speeds and in more complex environments, where the interaction with gusts is common. Such gusts can reach magnitudes comparable to the UAVs' flight speed, posing significant challenges to flight stability and control, especially during takeoff, landing, and hovering. One standardized model for these disturbances is the vortex gust, which has primarily been studied in two-dimensional configurations. In this work, we investigate the interaction between three-dimensional vortex gusts and rigid wings in incompressible flows at a chord-based Reynolds number up to 1000. We consider the effects of three-dimensional spanwise flow instabilities and examine how the gust interacts with the wing vortex shedding. To do so, we employ high-fidelity simulations using the spectral-element solver Nek5000 coupled with a space-adaptive computational framework that incorporates the adaptive mesh refinement (AMR) technique to automatically increase resolution where needed and reduce the computational cost. We discuss the unsteady aerodynamics during the vortex-wing interaction, presenting the aerodynamic coefficients, such as lift and drag, along with a detailed analysis of the flow structures.